Thread controller for sewing machines



Jan. 15, 1935. Cf F, RUBEL 1,988,051

THREAD CONTROLLER FOR SEWING MACHINES Fifed April 5. 1952 4 sheets-sheet 1 Cttomcg 45 Jan. 15, 1935. c. F, @www 1,988,051

THREAD CONTROLLER FOR SEWING MACHNES Filed April 1932 4 Sheets-Sheet 2 E im 'llllllull' 1H l L 35 ra Q2 .I

*yg L v l v :Snventor Smm *Gla GtornegS Jan. 15, 1935. c. F, RUBEL 1,988,051

THREAD CONTROLLER FOR SEWING MACHINES Filed April 5, 1932 4 Sheets-Sheet 3 `lam. 15, 1935.

c. F, RUBEL THREAD CONTROLLER FOR SEWING MACHINES F'led April 5. 1952 4 Sheets-Sheet 4 nventor Patented `lan. 15, 1935 THREAD CONTROLLER FOR SEWING MACHINES Charles F. Rubel, Chicago, Ill., assignor to Union Special Machine Company, Chicago, Ill., a corporation of Illinois Application April 5, 1932, Serial No. 603,291

11 Claims.

The invention relates to new and useful improvements in thread controllers for sewing machines, and more particularly to a thread controller for the machine of the type shown in the patent granted Norman V. Christensen and Frederick F. Zeier, March 25, 1930, No. 1,751,508. In this: machine, the looper and the needle are both operated from a shaft located above the work support and extending in the general direction ci the line of feed.

An object of the invention is to provide a machine of the above type with a thread controller for the needle and a thread controller for the looper, both of which are located adjacent and actuated by the upper shaft.

A further object of the invention is to provide a machine of the above type wherein the link which reciprocates the needle bar may be utilized for operating the thread controlling devices for the needle and the looper.

In the drawings- Figure l is a view in side elevation of a machine embodying the improvements, `the cover plates being removed in order to show the internal structure of the same;

Fig. 2 is a view partly in section and partly in front elevation, and showing more or less diagrammatically the looper, the needle and the thread controlling devices with the needle all the way up;

Fig. 3 is a similar view, but showing the looper on its backward movement;

Fig. 4 is a similar View, but showing the needle point well into the thread triangle formed by the looper thread extending from the eye of the looper to the previous stitch and the needle lcopwhich surrounds the looper;

Fig. 5 is a View showing the looper all the way back and the needle all the way down;

Fig. 6 is a detail showing in perspective the stationary needle thread engaging arm,

Fig. 7 is a detail in side elevation showing the stationary thread engaging arm and its relation to the sewing head.

Fig. 8 is a perspective view of the thread controller arm.

The machine to which the invention is applied is provided with an operating shaft which is located above the work support and which rextends in the general direction of the line of feed. The needle bar is located at the forward end of the shaft and is operated by a link connected to a crank carried by the end of the shaft. The looper oscillates in a plane at right angles to the line of feed and is given its oscilla- (Cl. Ilz-24.1)

tions and its needle avoiding movements from eccentrics on the main shaft. The feed is also given its backward and forward movements, and its up and down movements, by eccentrics on the main shaft. The thread controller for the 5 needle thread includes an arm which is xed to the link that reciprocates the needle bar. This arm has. an elongated thread eye in its outer end, and the thread passes through a stationary eyelet on the frame, then through theeye in 10 the arm, and thence through an eye at the top of the needle bar. There is also attached to the head of the machine, an arm having a thread engaging surface lying close to the path of reciprocation of the eye carried by the needle bar, 15 and this eye moves a slight distance beneath this thread engaging surface so as to "exert a pull on the thread in cooperation with the thread arm as the needle reaches the lower end of its stroke. ,1 This aids in the drawing up of the previous needle loop and also pulls some thread from the supply. The combined action of the thread eye at the upper end of the needle bar and the thread arm draws the thread taut as the needle reaches the upper end of its stroke, and pulls further thread fromv the supply.

There is a thread arm carried by the link which reciprocatesv the needle bar and has an eye through which the looper thread passes. The looper thread passes through a thread guide on the frame, thence through an eye inthe arm and thence through a thread guide on the needle head. The eye on the thread arm moves `across a line between the thread guides and operates to take up the looper thread on the backward movement of the looper, holding the looper thread taut as the point of the needle enters the thread triangle. It also cooperates with the eye on the frame in aiding the looper to draw off thread from the supply at the rear 40 end of the stroke of the looper.

Referring more in detail to 4the drawings, the improved thread controlling mechanism is shown as applied to a sewing machine having 5 a bed l carrying a work support 2. Extending upwardly from the bed 1 is a standard 3 carrying projecting arms 4 andI 5 in which a shaft 6 is mounted for rotation. The material is fed across the work support 2 by a feed dog 7 carried by a feed bar 8. The feed bar is raised and `lowered by an eccentric strap 9 cooperating with an eccentric on the main shaft 6. The feed bar is moved back and forth by an eccentric strap 10 cooperating with an eccentric on the main shaft 6. The material is held on the work support by a presser foot l1.

Projecting from the arm 5 is a bracket 12 carrying a sleeve 13 in which the needle bar 14 reciprocates. The needle bar carries a needle 15. The needle bar is reciprocated by means of a link 16 which is connected to a crank on the main shaft 6, and t'o a stud carried by the block 18 at the upper end of the needle bar. Cooperating with the needle beneath the work support is a thread carrying looper 19. The looper 19 is mounted on a looper carrier 20 which is pivoted at 21 to an arm carried by a support 22. The support 22 carries an arm 23 which is attached to an eccentric strap 24v cooperating with and eccentric on the main shaft 6. Pivotally' connected to the looper carrier 20 is a link 25 which is pivoted to an larm 26 carried by a shaft 27. There is a second arm attached to this shaft 27 which is connected to an eccentric strap 28 cooperating with an eccentric on the main shaft 6.

The present invention has particularly to do with the thread controlling mechanism both for the needle thread and the looper thread. The needle thread n passes from the supply through a suitable tension 29. From the tension it is led through a thread guide 30 attached to the frame. It then passes through a thread eye 31 in an arm 32 which is secured to the link 16 oy .screws 33, 33. The thread after passing through the eye 3l is led through a thread guide 34 at tached to the block 18 at the upper end of the needle bar. It then passes to the needle eye.

The looper thread indicated at l is led from the supply through a suitable tension 35 and thence to a thread guide 3G associated with the tension, and from this thread guide to a thread guide 37 formed in an arm 38 which is secured to the needle head 5 by a screw 39 passing through a slot 40 so that the arm may be raised and lowered. This arm carries an upwardly projecting lug 41. Adjacent this lug 41 on the upper edge of the arm is a thread engaging face 42 for the needle thread. The looper thread after leavingr the thread guide 37 passes through an eye 43 in an arm 44 which is attached to the link 18. As shown, the arms 32 and 44 are formed from one integral plate, and the screws 33, 33 secure both arms rigidly to the link. The

thread after leaving the eye 43 passes through a thread guide 45 attached to the needle head, thence through a thread guide 46 attached to the standard 3, and thence to the looper. It passes rst through the eye 47 at the heel of the looper and thence to the eye 48 at the point of the looper.

The operation of the needle thread controlling mechanism is as follows. When the needle is at the upper end of its stroke, as shown in Fig. 2 of the drawings, the eye 31 is well above the line passing through the thread guide 30 and the thread guide 34. The needle thread has been drawn taut and thread has been drawn from the supply as the arm reaches this position. The

looper at this time is at the forward end of its stroke. As the needle moves down, the thread is slackened by the downward movement of the thread guide 34 and the thread eye 3l. Thus slack thread is given to the needle, but under gradual control so as to avoid buckling of the thread in iront of the eye of the needle, but sufficient thread is given so as to insure the formation of the needle thread loop by the needle as it penetrates the fabric. As the needle approaches the lower end of its stroke, the needle thread is laid against the surface 42 at the upper edge of the forwardly projecting portion of the arm 38 which lies in the path of movement of the thread as it moves down with the needle bar. The continued downward movement of the needle bar after the thread contacts with this arm will draw on the needle thread, thus aiding the needle in drawing up the needle loop which was dropped from the looper to aid in setting the stitch, and it will also draw some thread from the supply at this time. As the needle moves upward, the arm 32 on its upward movement, together with the upward movement of the guide 34, will take all the slack out of the thread and will draw the thread tight, iinally setting the stitch and drawing further thread from the supply.

The looper thread controller moves across a line passing through the thread guide 37 and the thread guide 45. When the looper is reaching the forward end of its stroke, the thread eye 43 is moving toward the thread guide 37 with little downward movement as the link is approaching its vertical position with the needle bar controller raised. The crank 17 turns in a counter clockwise direction as viewed in Figures 2 to 5. In Fig. 3 of the drawings, the looper is shown as having been slightly retracted and the thread eye 43 is passing a line through the thread guides 37 and 45. The thread eye 43 will begin to pull on the looper thread. All slack is at this time taken out of the looper thread, so that the looper thread will be drawn substantially taut but not under strain, between the eye of the looper and the previous stitch, at the time when the needle point passes into the thread triangle as shown in Fig. 4. As the looper continues its retracting movement. slack is given to the looper thread. The eye 47 at the heel of the looper moves relative to the eye 46, so that it pulls on the thread. The parts are so timed and positioned that the looper cooperating with the thread eye 43 pulls thread from the supply as it reaches the forward end of its stroke. As the looper moves forward, slack is given to the thread so that the looper is free to move to the forward end of its stroke through the needle thread loop forming a looper thread loop without unduly straining the looper thread.

As the looper reaches the forward end of its stroke, the thread guide has taken all slack out of the thread and cooperates with the looper on its forward stroke in pulling thread from the supply.

From the above it will be noted. that the needle thread controlling mechanism is so constructed as to give suicient slack to the needle thread, so that at no time is the needle thread unduly strained. VA portion of the thread is drawn from the supply at the lower end of the stroke of the needle and the remainder at the upper end of the stroke of the needle. The looper thread controlling mechanism is also constructed and arranged to give suiiicient slack to the looper thread, so that the looper is at no time under severe strain. The looper thread is drawn from the supply in part when the looper is at the rear end of its stroke, and in part when the looper is at the forward end of its stroke. This produces a machine which may be run at high speed without breaking the sewing threads, even though when a relatively light or poor quality of thread is used.

It is obvious that minor changes in the details of construction and the arrangement of the parts may be made without departing from the spirit of the invention as set forth in the appended claims. v

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is

1. The combination of a bed, a work support carried thereby, a standard carried by the bed and disposed at one side of the work support, a feeding mechanism, an actuating shaft located above the plane of the work support and disposed so as to extend in the general direction of the line of feed and located substantially in rear of the stitching point, a needle bar mounted on said standard and actuated by said shaft, a needle carried thereby, a thread carrying looper located beneath the work support and operated from said shaft, and thread controlling devices for the needle thread and for the looper thread mounted above the work support and actuated by said shaft.

2. The combination of a bed, a work support carried thereby, a standard carried by the bed and disposed at one side of the work support, a feeding mechanism, an actuating shaft located above the plane of the work support and disposed so as to extend in the general direction of the line of feed and located substantially in rear of the stitching point, a needle bar mounted on said standard, a needle carried thereby, an operating member connected to said shaft and to the needle bar for reciprocating the same, a thread carrying looper located beneath the work support and operated from said shaft, and thread controlling devices for the needle thread and for the looper thread actuated by Said needle bar operating member.

3. The combination of a bed, a work support carried thereby, a standard carried by the bed and disposed at one side of the work support, a feeding mechanism, an actuating shaft located above the plane of the work support and disposed so as to extend in the general direction of the line of feed and located substantially in rear of the stitching point, a needle bar mounted on said standard, a needle carried thereby, an operating member connected to said shaft and to the needle bar for reciprocating the same, a thread carrying looper located beneath the work support and operated from said shaft, and aV thread controlling device for the looper thread, said controlling device being mounted on and actuated by said needle bar operating member.

4. The combination of a bed, a work support carried thereby, a standard carried by the bed and disposed at one side of the work support, a feeding mechanism, van actuating shaft located above the plane of the work support and disposed so as to extend in the general direction of the line of feed and located substantially in rear of the stitching point, a needle bar mounted on said standard, a needle carried thereby, a link connected to a crank on said shaft and to the needle bar for reciprocating the same, a thread carrying looper located beneath the work support and operated from said shaft, an arm carried by said link having a thread eye, thread guides associated therewith for controlling the needle thread, a second arm carried by said link having a thread eye, and thread guides associated with said last-named arm for controlling the looper thread.

5. The combination of a bed, a work support carried thereby, a standard carried by the bed and disposed at one side of the work support, a feeding mechanism, an actuating shaft located above the plane of the work support and disposed so as to extend in the general direction of the line of feed and located substantially in rear of the stitching point, a needle bar mounted on said standard, a needle carried thereby, a link connected to a crank on said shaft and to the needle bar for reciprocating the same, a thread carrying looper located beneath the Work support and operated from said shaft, a looper thread controlling mechanism in cluding an arm carried by said link having a thread eye, thread guides at opposite sides of the path of travel of the eye in said arm and disposed so that said arm Will take up the thread on the backward movement of the looper, drawing the thread taut as the needle point enters the thread triangle.

6. The combination of a bed, a work support carried thereby, a standard carried by the bed and disposed at one side of the work support, a feeding mechanism, an actuating shaft located above the plane of the work support and disposed so as to extend in the general direction of the line of feed and located substantially in rear of the stitching point, a needle bar mounted on said standard, a needle carried thereby, a link connected to a crank on said shaft and to the needle bar for reciprocating the same, a thread carrying looper located beneath the work support and operated from said shaft, a looper thread controlling mechanism including an arm carried by said link having a thread eye, thread guides at opposite sides of the path o1' travel df the eye in said arm and disposed so that said arm will cooperate with the looper in drawing a portion of the looper thread from the supply at the rear end of the stroke of the looper, and a portion of the looper thread from the supply at the forward end of the stroke of the looper.

7. A sewing machine including in combination, a work support, a needle bar, a shaft located above the work support and carrying a crank, a link connecting said crank to the needle bar for reciprocating the same, a thread carrying looper located beneath the work support, and thread controlling devices for the needle thread and the looper thread including arms mounted on said link and movable therewith and thread guides associated with each arm whereby said thread controlling devices operate independently on the needle thread and the looper thread.

8. A sewing machine including in combination, a Work support, a needle bar, a shaft located above the work support and carrying a crank, a link connecting said crank to the needle bar for reciprocating the same, a thread carrying looper located beneath the work support, thread controlling devices for the needle thread and the looper thread including arms mounted on said link, and thread'guides associated with each arm and disposed so that a thread eye in the end of each arm crosses lines through the respective thread guides.

9. A sewing machine including in combination a work support, a needle, a needle bar carrying the needle, a shaft located above the work support and carrying a crank, a link connecting the crank to the needle bar, a thread guide at the upper end of the needle bar, a stationary thread guide, an arm attached to the link and having an eye through which the needle thread passes from the stationary thread guide to the guide on the needle bar, said arm being disposed so that the thread eye crosses a line passing through said guides, and a stationary arm adjacent the path of the eye on the needle bar over which the needle thread is laid and cooperating with the movable thread arm on the link for pulling up the needle thread as the needle approaches the lower end ci its stroke.

l0. A sewing machine including in combination a work support, a needle bar, a shaft located above the Work support and carrying a crank, a linl; connecting said crank to the needle bar for reciprocating the same, a thread carrying looper located beneath the Work support, and thread controlling devices for the needle thread and the looper thread actuated by said link and operating independently for controlling the needle thread and the looper thread.

1l. In a sewing machine, the combination of a. needle head, a needle bar reciprocating therein, a needle carried by said needle bar, an operating shaft, a link connected to said operating shalt and said needle bar for reciprocating the same, cooperating thread controlling devices for the needle thread actuated by said needle bar and said needle bar actuating link, and a member carried by the needle head and so disposed as to Contact with the needle thread during the latter part of the down stroke of the needle whereby a pull-up action is exerted o: the needle thread as the needle approaches the lower end of its stroke continuing until said needle reaches the end of its stroke.

CHARLES F. RUBEL.

CII 

